May be more info than you want...
As I first attempted to install mine, I searched the internet for help and really found only one article that provided and useful help in the end. BMW dealerships in the DFW area don't seem to know how to deal with people that are willing to work on their own BMW. Anyway, I ran across your question a few weeks ago and decided if I did successfully install mine I would try to hit you back. So I have installed it and here goes:
The part number you received is the one I installed. If you need the installation instructions, the part number is 01 29 0 408 518. Found the PDF online. The kit BMW gave me only included the manual which did not have the installation instructions. The wiring harness they give you splits three of the wires coming from the car between the iPod interface and the radio, eliminating the need to cut any wires. It is a breeze to remove the radio unit and trim. I had difficulty trying to remove the bracket though.
Also, if you do not already know where all the screws are that allow access to the radio, you will need a technical manual for the car. There are also a few annoyances you will run into during installation. Of course, this is all if you are doing it yourself. I used one of the popular lines of automobile repair guides.
The iPod interface (after 2 weeks) seems to be doing fine. Everything is operating as described in the book. I'm not sure if this was described somewhere and I didn't read with an understanding, but in case you missed the same piece of information: I had functionality issues until I created each of the play lists as follows: BMW1 (99 tracks), BMW2 (25 tracks), BMW3 (99 tracks), BMW4 (99 tracks), BMW5 (99 tracks). For some reason, it seems to 'freak' out if a track was played that exceeded those track numbers on each play list and I would have to turn the radio, the iPod and sometimes the car to reset it if the CD display went over any of those numbers above.
The only reason this is going to matter is if you try to use any of the controls, it will stop responding and the iPod will usually continue running unless it starts 'skipping'. However, if you press play and leave the controls alone it will simply continue down the play list as long as there is music to play.
The pin pushing tool will save you a lot of time and hassle. If you try to remove the pins with something other than to tool, make sure you understand exactly how the locking mechanism in the wiring harness works. It is very easy to destroy the contacts as there is not much slack in the wire bundle (at least for me) to comfortably work. If you have the tool, the longest part of the installation is finding and removing the screws in the glove box and deactivating the SRS systems.
Don't know if you wanted to know all that, but I wish I knew going in. Glad to help with any other information from my experience if you want.